Platen printing press



July 12, 1938. F. s. THOMPSON PLATEN PRINTING PRESS Filed April 50', 1937 5 Sheets-Sheet 1 July 12, 1938. F. s. THOMPSON PLATEN PRINTING PRESS- Filed April 50, 1957 5 Sheets-Sheet 2 Jul 12, 1938. F, s, TH MP ON 2,123,516

PLATEN PRINTING PRESS Filed April 50, 1937 5 Sheets- Sheet s July 12, 1938. I ,F. s. THOMPSON PLATEN PRINTING PRESS Filed April 30, 1957 5 Sheets-Sheet 4 F. s. THQMPSON 2,123,516

Filed April 30, 1937 5 Sheets-Sheet 5 6% W1 w W F d X e PLATEN BRINTING PRESS Til/11f July 12, 1938.

Patented July 12, 1938 UNITED STATES PATENT OFFICE PLATEN PRINTING PRESS Application April 30,

1937, Serial No. 139,934

In Great Britain May 31, 1935 4 Claims.

This invention has reference to platen printing presses and to such presses wherein the printed sheets are removed from the movable platen by automatic means comprising a gripper device mounted and adapted to be reciprocated laterally of the platen, and which advances and seizes the printed sheet on the platen and then recedes and. removes the sheet which it subsequently releases and deposits.

In a known platen printing press of the kind referred to the delivery gripper device is mounted independently, and reciprocates laterally, of the movable platen and the seizing of the printed sheet by the device necessarily takes place when the platen has, or has nearly, reached the end of its return movement following the printing operation.

The object of the present invention is to provide in a platen printing press of the said kind, an improved arrangement of 'reciprocatory delivery gripper device whereby the device may seize the sheet as soon as the printing pressure has been applied to same, and during the return movement of the movable platen strips the printed sheet from the fixed platen and effects its removal from the movable platen.

According to the invention, the reciprocatory delivery gripper device is adapted to also oscillate about an axis, preferably the same axis as I the movable platen, parallel to its reciprocatory movements. By this means the gripper device can advance and be opened ready to seize the sheet during themovement of the platen to the printing position, be closed to grip the sheet as soon as the printing pressure has been applied and there is no danger of the register of the sheet being in any way affected, and after stripping the printed sheet from the fixed platen can recede and remove the sheet, during the return movement of the movable platen.

The invention is hereinafter fully described with reference to the accompanying drawings in which Fig. 1 is a part side of a platen printing press comprising one embodiment of the invention, Fig. 2 is a rear view (i. e. looking on the right hand side of Fig. 1) of the mechanism for actuating the delivery gripper device and Figs. 3 and 4 are elevations at right angles to each other to a larger scale than Figs. 1 and 2 showing details of the gripper-actuating mechanism not shown in such views. Fig. 5 is a plan of the gripper device, Figs. 6 and 7 are sections on the line X-X in Fig. 5 showing the hinged jaw of the gripper device closed and opened, respectively, and Figs. 8 and 9, are like sections to Figs. 6 and 7, respectively, on the line Y-Y in Fig. 5. On the drawings and in the following description like numerals of reference indicate like parts.

Referring to the drawings, 5, Fig. 1, indicates the frame of the machine, 6 indicates the stationary platen and 1 indicates the movable platen which is shown in the lowered or normal position in which the sheets to be printed are fed on to it. 8 indicates the pile of sheets to be printed carried on a support 9 arranged at the front of the machine. Hl indicates a feeding gripper device of the sucker type for feeding the sheets from the pile 8 on to the platen I. II indicates the delivery gripper device which is of the known kind comprising a fixed jaw and a hinged jaw normally closed against the fixed jaw. The fixed jaw of the gripper device consists of a blade li (Figs. 5-9) secured at its lower end to a support II The hinged jaw of the device is constituted by a plurality of fingers H clamped on a rod I I rotatably mounted in the blade I 1 The gripper device is in this particular embodiment of the invention arranged on the right-hand side of the movable platen as viewed from the front and, of course, on the left-hand side as seen from the rear as in Fig. 2. The support li of the gripper device is bifurcated and is pivotally mounted knuckle-joint fashion on a bush I 2 slidable on a slide bar 13 constituted by an extension of, or aligned with, the fulcrum shaft of the movable platenl. The support H of the gripper device is formed with a guide member Hi which co-acts with a guide bar l5 carried by and extending laterally from the movable platen l, the co-operation of the guide member l4 and bar 55 causing the gripper device I I to partake of the oscillations of the platen l.

The bush I2 is mounted in the upper end of a' slide IS the lower end of which has rotatably mounted in it a sleeve l1 adapted to slide on a slide bar 18 of square cross-section and mounted in the frame of the machine vertically below the slide bar l3.

To the slide I6 is pivotally connected at Ili one end of a lever l9 which at the midle l9 of its length has pivoted to it the free end of an arm 20, of length equal to half that of the lever, fixed on a shaft 2| on which is also fixed a gear wheel 22 gearing with a toothed quadrant 23 adapted to be oscillated from the main shaft of the machine by suitable means. The arm ll? of the lever l9 and the arm 20 constitute a toggle the opening and closing of which cause the slide 16 to reciprocate on the two slide bars l3, l8 and carry with it the gripper device I l. Conveniently,

and as shown, the quadrant 23 is fixed on a shaft 24 geared by means of bevels 25 with a shaft 26 carrying a toothed wheel 21 with which gears a quadrant 28 adapted to be oscillated by means of an arm 29 the free end of which carries a bowl 30 which co-operates with a cam groove 3| in a cam disc 32 suitably driven from the main shaft of the machine.

The wheel 22 is adapted to be oscillated by the quadrant 23 through 180 so that the arm 20 oscillates from a position in which it is horizontal on the left-hand side of the shaft 2|, as .viewed in Fig. 2, to a position in which it is horizontal on the right-hand side of the shaft, and vice versa, and the toggle members 20, I9 are fully opened and closed, and vice versa, on each side of the shaft 2|, alternately. In order to ensure that when the slide l6 reaches its mid-position in either direction of travel, and the toggle members 20, H! are closed and the pivot |6 coincides with the shaft 2|, the toggle member |9 shall not then move with the member 20 about the centre of the shaft 2|, but that the toggle members |9, 20 shall open on the other side of the shaft to continue the travel of the slide I6, the free end of the arm l9 of the lever I9 is provided with a bowl l9 adapted to enter and co-act with a vertical guide 33 arranged below and in vertical alignment with the shaft 2|. The co-operation of the bowl |9 with the guide 33 prevents the bowl from moving angularly about the centre of the shaft 2| and so causes the lever l9 to turn on its pivot I9 and the toggle members 20, I9 to open on the slide of the shaft 2| opposite to that on which they have just previously closed. In this way the toggle members during oscillation of the gear wheel 22 from one extreme position to the other, as aforesaid, first close on one side of the shaft 2| and then open on the other side of the shaft, and reciprocate the slide l6 and gripper device accordingly. The described construction of toggle has the advantage of enabling a maximum reciprocation of the slide l6 and gripper device tobe obtained with a minimum length of the toggle members 20, |9. The arrangement is such that while the gripper device ll partakes of the oscillations of the movable platen I, as before described, it advances towards the platen during the upward movement of the latter from the normal to the printing position and recedes from the platen during the return movement of the latter.

On the bush |2 on the upper slide bar I3 is mounted a cam disc 34 having a cam cavity 34 with which is adapted to co-operate a bowl 35* on one arm of a bell-crank lever 35 the other arm of which is connected with and adapted to open the hinged jaw of the gripper device I against the action of a spring 36 by means of which said jaw is normally kept closed. One end of the spring 36 is connected to an arm 3'! fixed on the fulcrum boss of the bell-crank lever 35 and its other end is anchored on the guide member M. The cam disc 34 carries a bowl 34 which cooperates in the bifurcated free end of an arm 38 fixed on the sleeve I! mounted on the lower square slide bar l8 which latter has fixed on it an arm Ili adapted to be operated through suitable means from the main cam of the machine, to rock the slide bar l8 to alter the angular position of the cam disc 34 and of the cam cavity 3 2 therein relatively to the bowl 35 which co-operates with same.

When, during the upward movement of the platen with a sheet to be printed upon it, the platen nears the printing position, the bowl 35 engages the upper part 34 of the cavity 34 in the cam 34 and operates the bell-crank lever 35 which through a link I and an arm H on the rod I i operates the latter to open the hinged jaw of the gripper device against the action of the spring 36, the hinged jaw remaining open while the sheet is being registered and until the application of the pressure of printing has actually commenced. The arm l8 on the lower square slide bar I8 is then actuated to rock the bar to cause the cam disc 34 to be so adjusted (clockwise as viewed in Fig. 3) relatively to the bowl 35 as to allow the hinged part I l of the gripper device l to be closed on the sheet by the action of the spring 36. During the subsequent return movement of the movable platen l the gripper device first oscillates therewith and strips the printed sheet from the type on the stationary platen 6 and then reciprocates away from the platen 1 and removes the printed sheet and the lower slide bar I8 is rocked in the opposite direction to formerly (i. e. in an anti-clockwise direction as viewed in Fig. 3) to restore the cam disc 34 to its original position. When the movable platen reaches the end of its return movement and the gripper device H the end of its outward reciprocation, the bowl 35 engages the lower part 34 of the cam cavity 34 and effects the opening of the hinged jaw of the gripper II to release the removed sheet and deposit same on a delivery pile 39 carried by a support 40.

I claim:-

1. In a platen printing press, the combination comprising an oscillatable platen, a gripper device for removing a printed sheet from the platen, means directly connecting the platen and the gripper device for effecting oscillation of the gripper device with the platen and means for reciprocating the gripper device along its axis of oscillation.

2. In a platen printing press, the combination comprising an oscillatable platen, a gripper device for removing a printed sheet from the platen, a member carried by the platen and slidably mounted in the gripper device for effecting oscillation of the gripper device with the platen, and means for reciprocating the gripper device along its axis of oscillation.

3. In a platen printing press the combination comprising a frame, an oscillatable platen mounted on the frame, a gripper device for removing a printed sheet from the platen, a member. carried by the platen and slidably mounted in the gripper device for effecting oscillation of the gripper device with the platen, and means for reciprocating the gripper device along its axis of oscillation including a toggle and a guide mounted on the frame and positioned to engage one element of the toggle.

4. In a platen printing press the combination comprising an oscillatable platen, a gripper device for removing a printed sheet from the platen, means directly connecting the platen and the gripper device for effecting oscillation of the gripper device with the platen, means for reciprocating the gripper device along its axis of oscillation, and means for actuating the grippers of the gripper device including a cam mounted for reciprocating movement with the gripper device and means for effecting angular movement of the cam.

FRANK SYDNEY THOMPSON. 

